Non-volatile memory devices such as flash memory devices are used to store data or information. Flash memory devices reside in many computers and electronic devices, for example, cellular phones, digital cameras, digital audio players, and digital recorders. Flash memory devices may also be used as portable storage devices such as portable Universal Serial Bus (USB) flash drives or “thumb” drives. In some cases, flash memory devices may substitute for conventional magnetic hard drives in computers and other electronic devices or systems.
A flash memory device stores information in numerous memory cells, which are usually formed in a semiconductor chip. A flash memory device usually has a programming or writing operation to store information in the cells, a read operation to read information from the cells, and an erase operation to erase or delete information from the cells.
The information stored in the flash memory device may be updated. In some cases the same information may be updated many times. Thus, in some update technique such as out-of-place update, many instances of the information may exist. Some flash memory devices may manage the instances of the information by giving each instance a different version identification value. The device may store the version identification value in some reserved space in the device. At some point, the quantity of instances of the information may become large. Thus, version identification value may also become large which may overflow the reserved space. Therefore, there is a need for methods, apparatus, and systems to improve management of information in flash memory device.